Fieldbus refers to a network primarily used for digital communication between measurement and control machines within a factory. It specializes in communication between sensors, various operator terminals, and controllers, as well as communication between controllers themselves. This article focuses on the characteristics of fieldbus and the different types of fieldbuses.
What are the characteristics of fieldbus?
Adaptability to field environments. Fieldbus is designed to work in field environments and can support twisted-pair cables, coaxial cables, optical fibers, radio frequency, infrared, and power lines. It has strong anti-interference capabilities, can use two-wire systems for power transmission and communication, and can meet safety and explosion-proof requirements.
Fieldbus technology makes systems more flexible. In CNC machine tools, various controllers, actuators, and sensors are connected via fieldbus, resulting in fewer cables, easier installation, lower implementation costs, more flexible system design, higher signal transmission reliability, and stronger anti-interference capabilities. Fieldbus-based control systems for CNC machine tools will gradually replace traditional control systems, and complex wiring harnesses will be replaced by fieldbuses. According to available information, a bus-based CNC system for high-end CNC machine tools has been successfully developed in China, supporting 32 axes, 6 channels, 768IN/512OUT switch control, and allowing for user-defined secondary development.
What are the different types of fieldbus?
FF fieldbus
In 1994, the FF Foundation was established through the merger of the ISP Foundation and World FIP (North America), with the aim of developing a unique international fieldbus (Fundation Fieldbus) compliant with IEC and ISO standards. The low-speed bus (H1) protocol was published in 1996. The high-speed bus (H2), whose development was completed, was planned for release in 1998. In May 1997, the China Fieldbus (FF) Professional Committee was established, and preparations were made for the establishment of an FF fieldbus product certification center.
LONWORKS bus
LONWORKS fieldbus stands for LONWORKS NetWorks, a distributed intelligent control network technology aimed at providing measurement and control networks suitable for various fieldbus applications. Currently, LONWORKS has a wide range of applications, primarily including industrial control, building automation, data acquisition, and SCADA systems.
CANBUS Fieldbus
The CANBUS fieldbus has been approved by the ISO/TC22 technical committee as an international standard ISO 11898 (communication rate less than 1 Mbps) and ISO 11519 (communication rate less than 125 Kbps). CANBUS products are mainly used in automotive manufacturing, public transportation vehicles, robotics, hydraulic systems, and distributed I/O. It also finds applications in elevators, medical devices, machine tools, and building automation.
P-NET Fieldbus
The P-NET fieldbus was initiated in 1983. In 1986, multiple network structures and multiple interface functions were added to the communication protocol. In 1987, P-NET multi-interface products were launched. In 1987, the P-NET standard became a Danish national standard. In 1996, it became part of the European bus standard (EN 50170 V.1).
Regarding fieldbus, this article focuses on the characteristics of fieldbus and the different types of fieldbuses. Essentially, a fieldbus is a local area network (LAN) that is described using standards. Its hardware, software, and protocols adhere to these standards and are used as a communication method in control systems.
